1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
require "opengl"
require "glut"
require "rational"
RAMPSIZE=16
RAMP1START=32
RAMP2START=48
STDOUT.sync = TRUE
$rotAngle = 0
# Initialize antialiasing for color index mode,
# including loading a green color ramp starting
# at RAMP1START, and a blue color ramp starting
# at RAMP2START. The ramps must be a multiple of 16.
def myinit
for i in (0..RAMPSIZE)
shade = i.to_f/RAMPSIZE.to_f;
GLUT.SetColor(RAMP1START+i, 0, shade, 0.0);
GLUT.SetColor(RAMP2START+i, 0, 0, shade);
end
GL.Enable(GL::LINE_SMOOTH);
GL.Hint(GL::LINE_SMOOTH_HINT, GL::DONT_CARE);
GL.LineWidth(1.5);
GL.ClearIndex(RAMP1START);
end
display = Proc.new {
GL.Clear(GL::COLOR_BUFFER_BIT);
GL.Indexi(RAMP1START);
GL.PushMatrix();
GL.Rotate(-$rotAngle, 0.0, 0.0, 0.1);
GL.Begin(GL::LINES);
GL.Vertex(-0.5, 0.5);
GL.Vertex(0.5, -0.5);
GL.End
GL.PopMatrix();
GL.Indexi(RAMP2START);
GL.PushMatrix();
GL.Rotate($rotAngle, 0.0, 0.0, 0.1);
GL.Begin(GL::LINES);
GL.Vertex(0.5, 0.5);
GL.Vertex(-0.5, -0.5);
GL.End
GL.PopMatrix();
GL.Flush();
}
reshape = Proc.new {|w, h|
GL.Viewport(0, 0, w, h);
GL.MatrixMode(GL::PROJECTION);
GL.LoadIdentity();
if (w <= h)
GLU.Ortho2D(-1.0, 1.0, -h.to_f/w.to_f, h.to_f/w.to_f);
else
GLU.Ortho2D(w.to_f/h.to_f, w.to_f/h.to_f, -1.0, 1.0);
end
GL.MatrixMode(GL::MODELVIEW);
GL.LoadIdentity();
}
keyboard = Proc.new {|key, x, y|
case (key)
when 'r'[0]
$rotAngle += 20
$rotAngle = 0 if ($rotAngle >= 360)
GLUT.PostRedisplay();
when 'R'[0]
$rotAngle -= 20
$rotAngle = 360 if ($rotAngle <= 0)
GLUT.PostRedisplay();
when 27
exit(0);
end
}
# Main Loop
# Open window with initial window size, title bar,
# color index display mode, and handle input events.
#
GLUT.Init
GLUT.InitDisplayMode (GLUT::SINGLE | GLUT::INDEX);
GLUT.InitWindowSize(200, 200);
GLUT.CreateWindow($0);
myinit
GLUT.ReshapeFunc(reshape);
GLUT.KeyboardFunc(keyboard);
GLUT.DisplayFunc(display);
GLUT.MainLoop
|
